Optoelectronic modules employing triangulation and/or emitted-light techniques may be used to measure distance to a scene and/or recreate a multi-dimensional rendering of a scene (e.g., recreation of a scene in three dimensions or recreation of a moving scene in three dimensions as a function of time). A triangulation technique may employ an imager and a light emitter. The precision and/or suitability of a distance measurement may be largely a function of the baseline distance between the imager and light emitter. For example, large baselines usually produce smaller errors in distance measurements; however, objects or scenes in closer proximity to the imager may be occluded (i.e., outside of the field of view of either the imager or light emitter). Consequently, in some cases, larger baselines are more suitable for scenes or objects at longer distances, while in other cases smaller baselines are more suitable for scenes or objects at shorter distances. However, miniaturization of technology, for example personal consumer technology such as smart phones, prevents the implementation of large baselines in optoelectronic modules for proximity measurements and/or multi-dimensional imaging.
Other techniques may be employed for accurate distance measurements. Optoelectronic modules using time of flight (TOF) technology are suitable for measuring the distance of scenes at long/far distances. TOF requires a modulated light emitter to direct modulated light onto an object/scene, and an imager (TOF imager) including an optical assembly and sensor. The sensor includes de-modulation pixels (TOF pixels) that may derive distance information from the change in phase of modulated light reflected by a scene. The precision/accuracy/suitability of the technique is not strongly dependent on the baseline distance between the TOF imager and modulated light emitter. The TOF technique, however, may have some drawbacks; for example, data derived from the TOF technique may suffer from multi-path distance errors.
Accordingly, an optoelectronic module is needed that: 1) can combine precise/suitable measurements of scenes over a range of short distances (e.g., sub-centimeter) to long distances (e.g., 20 meters or even 30 meters or more), 2) occupies a small footprint, and 3) mitigates multi-path distance errors.